Evolution of chinook salmon (Oncorhynchus tshawytscha) populations in New Zealand: pattern, rate, and process.
Evolution of chinook salmon (Oncorhynchus tshawytscha) populations in New Zealand: pattern, rate, and process.
复制标题
新西兰奇努克鲑鱼（Oncorhynchus tshawytscha）种群的进化：模式、速率和过程。
DOI：
10.1007/978-94-010-0585-2_30
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发表时间：
2001
期刊：
影响因子：
1.5
通讯作者：
M. Unwin
中科院分区：
文献类型：
--
作者：
T. Quinn;M. Kinnison;M. Unwin
奇努克鲑鱼，Oncorhynchus tshawytscha，来自萨克拉门托河，加州，美国被引入新西兰之间的1901年和1907年，并殖民了大部分的今天的范围内约10年。新西兰的鲑鱼种群现在在自然分布范围内通常用于区分鲑鱼种群的表型特征各不相同：在淡水和海洋中的生长，成熟年龄，返回淡水和繁殖的日期，形态和繁殖分配。本文回顾了一个大型的研究计划，旨在确定表型可塑性和遗传适应这种变化的相对贡献，在努力了解新种群的自然进化的过程。我们发现强有力的证据表明，在最多30代内，种群之间的性状差异，特别是在淡水生长率，回归日期和生殖输出，这些差异与合理的适应基础。重要的是，我们还证明了不仅是释放后生存的遗传基础，但更高的生存，因此健身，人口从其建立的网站相比，另一个人口从同一网站发布。我们得出结论，不同河流中鲑鱼的差异最初可能是由于表型可塑性（例如，栖息地特异性生长率，以及上游迁移对卵巢投资的影响）。亲崇拜（归巢于纳塔尔流）与不同繁殖期的快速进化相结合，限制了基因流动，促进了其他性状的分化。我们还建议，除了随机创始人效应导致的遗传分歧，分歧也可能会出现在殖民化的早期阶段，当原始殖民者是一个非随机的，预先适应的子集的源人口。这种“受青睐的创始人效应”立即提高了新人口的适应性。总的来说，这项研究揭示了环境和遗传控制对行为，生理和生活史的复杂相互作用，这些都是种群分化早期阶段的特征，这一过程在鲑鱼种群的历史上反复发生。
Chinook salmon, Oncorhynchus tshawytscha, from the Sacramento River, California, USA were introduced to New Zealand between 1901 and 1907, and colonized most of their present-day range within about 10 years. The New Zealand populations now vary in phenotypic traits typically used to differentiate salmon populations within their natural range: growth in freshwater and at sea, age at maturity, dates of return to fresh water and reproduction, morphology, and reproductive allocation. This paper reviews a large research program designed to determine the relative contributions of phenotypic plasticity and genetic adaptation to this variation, in an effort to understand the processes underlying the natural evolution of new populations. We found strong evidence of trait divergence between populations within at most 30 generations, particularly in freshwater growth rate, date of return, and reproductive output, with plausible adaptive bases for these differences. Importantly, we also demonstrated not only a genetic basis for post-release survival but higher survival, and hence fitness, of a population released from its established site compared to another population released from the same site. We conclude that divergence of salmon in different rivers probably resulted initially from phenotypic plasticity (e.g., habitat-specific growth rates, and effects of upriver migration on ovarian investment). Philopatry (homing to natal streams) combined with rapid evolution of distinct breeding periods to restrict gene flow, facilitating divergence in other traits. We also suggest that in addition to genetic divergence resulting from random founder effects, divergence may also arise during the very early stages of colonization when the original colonists are a non-random, pre-adapted subset of the source population. This ‘favored founders effect’ immediately improves the fitness of the new population. Overall, this research reveals the complex interplay of environmental and genetic controls over behavior, physiology and life history that characterize the early stages of population differentiation, a process that has taken place repeatedly during the history of salmon populations.